Dual battery wiring tutorial (and why)

[bubbagumper6 5,000+ posts]

No, they don't have to be the same battery. Some will tell you this will shorten the life of them if you don't use an isolator, however I've never used one and I'm still using the used yellowtop I bought over 4 years ago so take that as you will....

Adding a second battery will put more strain on your alternator but the problem isn't necessarily adding the battery it's the underlying problem of you drawing more power than what your alternator can produce. If your just running that 1200 and 300 (1500w total?) you're on the brink of needing an aftermarket alternator. Depending on the stock size you could probably run it for awhile with the two batts but then you run the risk of totally killing the alternator at some random point in the future which will leave you stranded without a car....

 

[swollen_cu 10+ year member]

No, they don't have to be the same battery. Some will tell you this will shorten the life of them if you don't use an isolator, however I've never used one and I'm still using the used yellowtop I bought over 4 years ago so take that as you will....
Adding a second battery will put more strain on your alternator but the problem isn't necessarily adding the battery it's the underlying problem of you drawing more power than what your alternator can produce. If your just running that 1200 and 300 (1500w total?) you're on the brink of needing an aftermarket alternator. Depending on the stock size you could probably run it for awhile with the two batts but then you run the risk of totally killing the alternator at some random point in the future which will leave you stranded without a car....

Thanks for clearing that up. I might get my alternator either rewound or buy an aftermarket one. Any reputable companies besides DC alternators to buy from? How are the ones on ebay?

 

[bubbagumper6 5,000+ posts]

Thanks for clearing that up. I might get my alternator either rewound or buy an aftermarket one. Any reputable companies besides DC alternators to buy from? How are the ones on ebay?

I believe the other recommended company is Mechman but I have no experience with them so I can't vouch for them. Same with ebay, I wouldn't personally buy an alt from ebay but I believe there's members on here that have. You'll just have to search around, you'll find your answers.

 

[jakkit_lee]

Battery power is not the same problem in my charge.

battery 1 = 75 Ah and battery 2 = 200 Ah

Thank you.

 

[kramer_212 10+ year member]

pictures are worth 1000 words, truly

 

[Dxtr315]

I got two batteries same brand but one is older, would i need to install a isolator? If so where would it fit in the picture